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Fix #3400, ignore server-provided failover partner #3625

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Merged
mdaigle merged 8 commits into from
Sep 29, 2025
Merged

Fix #3400, ignore server-provided failover partner #3625

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1b9b8eb
Add IgnoreServerProvidedFailoverPartner app context switch.
mdaigle Sep 22, 2025
35eda78
Add behavior skip to netfx.
mdaigle Sep 22, 2025
de0fafe
Consolidate to single property for failover partner value.
mdaigle Sep 22, 2025
6a36110
Rework checks to preserve server provided value, but ignore it.
mdaigle Sep 22, 2025
99fe120
Fix import.
mdaigle Sep 22, 2025
92741c4
Merge branch 'main' of github.com:dotnet/SqlClient into dev/mdaigle/3…
mdaigle Sep 22, 2025
a5c9a18
Merge branch 'main' of github.com:dotnet/SqlClient into dev/mdaigle/3…
mdaigle Sep 25, 2025
5e0b12e
Skip server failover partner override in ŒLoginNoFailover method. Add…
mdaigle Sep 26, 2025
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2 changes: 1 addition & 1 deletion src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/SqlCommand.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -3690,7 +3690,7 @@ private void CheckNotificationStateAndAutoEnlist()
}

Notification.Options = SqlDependency.GetDefaultComposedOptions(_activeConnection.DataSource,
InternalTdsConnection.ServerProvidedFailOverPartner,
InternalTdsConnection.ServerProvidedFailoverPartner,
identityUserName, _activeConnection.Database);
}

Expand Down
58 changes: 33 additions & 25 deletions ...Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/SqlInternalConnectionTds.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -314,7 +314,6 @@ internal SessionData CurrentSessionData
// FOR CONNECTION RESET MANAGEMENT
private bool _fResetConnection;
private string _originalDatabase;
private string _currentFailoverPartner; // only set by ENV change from server
private string _originalLanguage;
private string _currentLanguage;
private int _currentPacketSize;
Expand Down Expand Up @@ -704,13 +703,7 @@ internal TdsParser Parser
}
}

internal string ServerProvidedFailOverPartner
{
get
{
return _currentFailoverPartner;
}
}
internal string ServerProvidedFailoverPartner { get; set; }

internal SqlConnectionPoolGroupProviderInfo PoolGroupProviderInfo
{
Expand Down Expand Up @@ -1507,7 +1500,7 @@ private void OpenLoginEnlist(TimeoutTimer timeout,
throw SQL.ROR_FailoverNotSupportedConnString();
}

if (ServerProvidedFailOverPartner != null)
if (ServerProvidedFailoverPartner != null)
{
throw SQL.ROR_FailoverNotSupportedServer(this);
}
Expand Down Expand Up @@ -1635,7 +1628,7 @@ private void LoginNoFailover(ServerInfo serverInfo,
newSecurePassword,
attemptOneLoginTimeout);

if (connectionOptions.MultiSubnetFailover && ServerProvidedFailOverPartner != null)
if (connectionOptions.MultiSubnetFailover && ServerProvidedFailoverPartner != null)
{
// connection succeeded: trigger exception if server sends failover partner and MultiSubnetFailover is used
throw SQL.MultiSubnetFailoverWithFailoverPartner(serverProvidedFailoverPartner: true, internalConnection: this);
Expand Down Expand Up @@ -1663,7 +1656,7 @@ private void LoginNoFailover(ServerInfo serverInfo,
_currentPacketSize = ConnectionOptions.PacketSize;
_currentLanguage = _originalLanguage = ConnectionOptions.CurrentLanguage;
CurrentDatabase = _originalDatabase = ConnectionOptions.InitialCatalog;
_currentFailoverPartner = null;
ServerProvidedFailoverPartner = null;
_instanceName = string.Empty;

routingAttempts++;
Expand Down Expand Up @@ -1702,7 +1695,7 @@ private void LoginNoFailover(ServerInfo serverInfo,
// We only get here when we failed to connect, but are going to re-try

// Switch to failover logic if the server provided a partner
if (ServerProvidedFailOverPartner != null)
if (ServerProvidedFailoverPartner != null)
{
if (connectionOptions.MultiSubnetFailover)
{
Expand All @@ -1718,7 +1711,7 @@ private void LoginNoFailover(ServerInfo serverInfo,
LoginWithFailover(
true, // start by using failover partner, since we already failed to connect to the primary
serverInfo,
ServerProvidedFailOverPartner,
ServerProvidedFailoverPartner,
newPassword,
newSecurePassword,
redirectedUserInstance,
Expand All @@ -1740,8 +1733,8 @@ private void LoginNoFailover(ServerInfo serverInfo,
{
// We must wait for CompleteLogin to finish for to have the
// env change from the server to know its designated failover
// partner; save this information in _currentFailoverPartner.
PoolGroupProviderInfo.FailoverCheck(false, connectionOptions, ServerProvidedFailOverPartner);
// partner; save this information in ServerProvidedFailoverPartner.
PoolGroupProviderInfo.FailoverCheck(false, connectionOptions, ServerProvidedFailoverPartner);
}
CurrentDataSource = originalServerInfo.UserServerName;
}
Expand Down Expand Up @@ -1802,7 +1795,7 @@ TimeoutTimer timeout
ServerInfo failoverServerInfo = new ServerInfo(connectionOptions, failoverHost, connectionOptions.FailoverPartnerSPN);

ResolveExtendedServerName(primaryServerInfo, !redirectedUserInstance, connectionOptions);
if (ServerProvidedFailOverPartner == null)
if (ServerProvidedFailoverPartner == null)
{
ResolveExtendedServerName(failoverServerInfo, !redirectedUserInstance && failoverHost != primaryServerInfo.UserServerName, connectionOptions);
}
Expand Down Expand Up @@ -1861,12 +1854,21 @@ TimeoutTimer timeout
failoverDemandDone = true;
}

// Primary server may give us a different failover partner than the connection string indicates. Update it
if (ServerProvidedFailOverPartner != null && failoverServerInfo.ResolvedServerName != ServerProvidedFailOverPartner)
// Primary server may give us a different failover partner than the connection string indicates.
// Update it only if we are respecting server-provided failover partner values.
if (ServerProvidedFailoverPartner != null && failoverServerInfo.ResolvedServerName != ServerProvidedFailoverPartner)
{
SqlClientEventSource.Log.TryAdvancedTraceEvent("<sc.SqlInternalConnectionTds.LoginWithFailover|ADV> {0}, new failover partner={1}", ObjectID, ServerProvidedFailOverPartner);
failoverServerInfo.SetDerivedNames(string.Empty, ServerProvidedFailOverPartner);
if (LocalAppContextSwitches.IgnoreServerProvidedFailoverPartner)
{
SqlClientEventSource.Log.TryTraceEvent("<sc.SqlInternalConnectionTds.LoginWithFailover|ADV> {0}, Ignoring server provided failover partner '{1}' due to IgnoreServerProvidedFailoverPartner AppContext switch.", ObjectID, ServerProvidedFailoverPartner);
}
else
{
SqlClientEventSource.Log.TryAdvancedTraceEvent("<sc.SqlInternalConnectionTds.LoginWithFailover|ADV> {0}, new failover partner={1}", ObjectID, ServerProvidedFailoverPartner);
failoverServerInfo.SetDerivedNames(string.Empty, ServerProvidedFailoverPartner);
}
}

currentServerInfo = failoverServerInfo;
_timeoutErrorInternal.SetInternalSourceType(SqlConnectionInternalSourceType.Failover);
}
Expand Down Expand Up @@ -1916,7 +1918,7 @@ TimeoutTimer timeout
_currentPacketSize = connectionOptions.PacketSize;
_currentLanguage = _originalLanguage = ConnectionOptions.CurrentLanguage;
CurrentDatabase = _originalDatabase = connectionOptions.InitialCatalog;
_currentFailoverPartner = null;
ServerProvidedFailoverPartner = null;
_instanceName = string.Empty;

AttemptOneLogin(
Expand Down Expand Up @@ -1978,7 +1980,7 @@ TimeoutTimer timeout
_activeDirectoryAuthTimeoutRetryHelper.State = ActiveDirectoryAuthenticationTimeoutRetryState.HasLoggedIn;

// if connected to failover host, but said host doesn't have DbMirroring set up, throw an error
if (useFailoverHost && ServerProvidedFailOverPartner == null)
if (useFailoverHost && ServerProvidedFailoverPartner == null)
{
throw SQL.InvalidPartnerConfiguration(failoverHost, CurrentDatabase);
}
Expand All @@ -1987,8 +1989,13 @@ TimeoutTimer timeout
{
// We must wait for CompleteLogin to finish for to have the
// env change from the server to know its designated failover
// partner; save this information in _currentFailoverPartner.
PoolGroupProviderInfo.FailoverCheck(useFailoverHost, connectionOptions, ServerProvidedFailOverPartner);
// partner.

// When ignoring server provided failover partner, we must pass in the original failover partner from the connection string.
// Otherwise the pool group's failover partner designation will be updated to point to the server provided value.
string actualFailoverPartner = LocalAppContextSwitches.IgnoreServerProvidedFailoverPartner ? failoverHost : ServerProvidedFailoverPartner;

PoolGroupProviderInfo.FailoverCheck(useFailoverHost, connectionOptions, actualFailoverPartner);
}
CurrentDataSource = (useFailoverHost ? failoverHost : primaryServerInfo.UserServerName);
}
Expand Down Expand Up @@ -2218,7 +2225,8 @@ internal void OnEnvChange(SqlEnvChange rec)
{
throw SQL.ROR_FailoverNotSupportedServer(this);
}
_currentFailoverPartner = rec._newValue;

ServerProvidedFailoverPartner = rec._newValue;
break;

case TdsEnums.ENV_PROMOTETRANSACTION:
Expand Down
2 changes: 1 addition & 1 deletion src/Microsoft.Data.SqlClient/netfx/src/Microsoft/Data/SqlClient/SqlCommand.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -3569,7 +3569,7 @@ private void CheckNotificationStateAndAutoEnlist()
}

Notification.Options = SqlDependency.GetDefaultComposedOptions(_activeConnection.DataSource,
InternalTdsConnection.ServerProvidedFailOverPartner,
InternalTdsConnection.ServerProvidedFailoverPartner,
identityUserName, _activeConnection.Database);
}

Expand Down
57 changes: 32 additions & 25 deletions src/Microsoft.Data.SqlClient/netfx/src/Microsoft/Data/SqlClient/SqlInternalConnectionTds.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -326,7 +326,6 @@ internal SessionData CurrentSessionData
// FOR CONNECTION RESET MANAGEMENT
private bool _fResetConnection;
private string _originalDatabase;
private string _currentFailoverPartner; // only set by ENV change from server
private string _originalLanguage;
private string _currentLanguage;
private int _currentPacketSize;
Expand Down Expand Up @@ -714,13 +713,7 @@ internal TdsParser Parser
}
}

internal string ServerProvidedFailOverPartner
{
get
{
return _currentFailoverPartner;
}
}
internal string ServerProvidedFailoverPartner { get; set; }

internal SqlConnectionPoolGroupProviderInfo PoolGroupProviderInfo
{
Expand Down Expand Up @@ -1515,7 +1508,7 @@ private void OpenLoginEnlist(TimeoutTimer timeout,
throw SQL.ROR_FailoverNotSupportedConnString();
}

if (ServerProvidedFailOverPartner != null)
if (ServerProvidedFailoverPartner != null)
{
throw SQL.ROR_FailoverNotSupportedServer(this);
}
Expand Down Expand Up @@ -1665,7 +1658,7 @@ private void LoginNoFailover(ServerInfo serverInfo,
isFirstTransparentAttempt: isFirstTransparentAttempt,
disableTnir: disableTnir);

if (connectionOptions.MultiSubnetFailover && ServerProvidedFailOverPartner != null)
if (connectionOptions.MultiSubnetFailover && ServerProvidedFailoverPartner != null)
{
// connection succeeded: trigger exception if server sends failover partner and MultiSubnetFailover is used
throw SQL.MultiSubnetFailoverWithFailoverPartner(serverProvidedFailoverPartner: true, internalConnection: this);
Expand Down Expand Up @@ -1693,7 +1686,7 @@ private void LoginNoFailover(ServerInfo serverInfo,
_currentPacketSize = ConnectionOptions.PacketSize;
_currentLanguage = _originalLanguage = ConnectionOptions.CurrentLanguage;
CurrentDatabase = _originalDatabase = ConnectionOptions.InitialCatalog;
_currentFailoverPartner = null;
ServerProvidedFailoverPartner = null;
_instanceName = string.Empty;

routingAttempts++;
Expand Down Expand Up @@ -1732,7 +1725,7 @@ private void LoginNoFailover(ServerInfo serverInfo,
// We only get here when we failed to connect, but are going to re-try

// Switch to failover logic if the server provided a partner
if (ServerProvidedFailOverPartner != null)
if (ServerProvidedFailoverPartner != null)
{
if (connectionOptions.MultiSubnetFailover)
{
Expand All @@ -1748,7 +1741,7 @@ private void LoginNoFailover(ServerInfo serverInfo,
LoginWithFailover(
true, // start by using failover partner, since we already failed to connect to the primary
serverInfo,
ServerProvidedFailOverPartner,
ServerProvidedFailoverPartner,
newPassword,
newSecurePassword,
redirectedUserInstance,
Expand All @@ -1770,8 +1763,8 @@ private void LoginNoFailover(ServerInfo serverInfo,
{
// We must wait for CompleteLogin to finish for to have the
// env change from the server to know its designated failover
// partner; save this information in _currentFailoverPartner.
PoolGroupProviderInfo.FailoverCheck(false, connectionOptions, ServerProvidedFailOverPartner);
// partner; save this information in ServerProvidedFailoverPartner.
PoolGroupProviderInfo.FailoverCheck(false, connectionOptions, ServerProvidedFailoverPartner);
}
CurrentDataSource = originalServerInfo.UserServerName;
}
Expand Down Expand Up @@ -1855,7 +1848,7 @@ TimeoutTimer timeout
ServerInfo failoverServerInfo = new ServerInfo(connectionOptions, failoverHost, connectionOptions.FailoverPartnerSPN);

ResolveExtendedServerName(primaryServerInfo, !redirectedUserInstance, connectionOptions);
if (ServerProvidedFailOverPartner == null)
if (ServerProvidedFailoverPartner == null)
{
ResolveExtendedServerName(failoverServerInfo, !redirectedUserInstance && failoverHost != primaryServerInfo.UserServerName, connectionOptions);
}
Expand Down Expand Up @@ -1912,12 +1905,21 @@ TimeoutTimer timeout
failoverDemandDone = true;
}

// Primary server may give us a different failover partner than the connection string indicates. Update it
if (ServerProvidedFailOverPartner != null && failoverServerInfo.ResolvedServerName != ServerProvidedFailOverPartner)
// Primary server may give us a different failover partner than the connection string indicates.
// Update it only if we are respecting server-provided failover partner values.
if (ServerProvidedFailoverPartner != null && failoverServerInfo.ResolvedServerName != ServerProvidedFailoverPartner)
{
SqlClientEventSource.Log.TryAdvancedTraceEvent("<sc.SqlInternalConnectionTds.LoginWithFailover|ADV> {0}, new failover partner={1}", ObjectID, ServerProvidedFailOverPartner);
failoverServerInfo.SetDerivedNames(protocol, ServerProvidedFailOverPartner);
if (LocalAppContextSwitches.IgnoreServerProvidedFailoverPartner)
{
SqlClientEventSource.Log.TryTraceEvent("<sc.SqlInternalConnectionTds.LoginWithFailover|ADV> {0}, Ignoring server provided failover partner '{1}' due to IgnoreServerProvidedFailoverPartner AppContext switch.", ObjectID, ServerProvidedFailoverPartner);
}
else
{
SqlClientEventSource.Log.TryAdvancedTraceEvent("<sc.SqlInternalConnectionTds.LoginWithFailover|ADV> {0}, new failover partner={1}", ObjectID, ServerProvidedFailoverPartner);
failoverServerInfo.SetDerivedNames(protocol, ServerProvidedFailoverPartner);
}
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}

currentServerInfo = failoverServerInfo;
_timeoutErrorInternal.SetInternalSourceType(SqlConnectionInternalSourceType.Failover);
}
Expand Down Expand Up @@ -1967,7 +1969,7 @@ TimeoutTimer timeout
_currentPacketSize = connectionOptions.PacketSize;
_currentLanguage = _originalLanguage = ConnectionOptions.CurrentLanguage;
CurrentDatabase = _originalDatabase = connectionOptions.InitialCatalog;
_currentFailoverPartner = null;
ServerProvidedFailoverPartner = null;
_instanceName = string.Empty;

AttemptOneLogin(
Expand Down Expand Up @@ -2029,7 +2031,7 @@ TimeoutTimer timeout
_activeDirectoryAuthTimeoutRetryHelper.State = ActiveDirectoryAuthenticationTimeoutRetryState.HasLoggedIn;

// if connected to failover host, but said host doesn't have DbMirroring set up, throw an error
if (useFailoverHost && ServerProvidedFailOverPartner == null)
if (useFailoverHost && ServerProvidedFailoverPartner == null)
{
throw SQL.InvalidPartnerConfiguration(failoverHost, CurrentDatabase);
}
Expand All @@ -2038,8 +2040,13 @@ TimeoutTimer timeout
{
// We must wait for CompleteLogin to finish for to have the
// env change from the server to know its designated failover
// partner; save this information in _currentFailoverPartner.
PoolGroupProviderInfo.FailoverCheck(useFailoverHost, connectionOptions, ServerProvidedFailOverPartner);
// partner.

// When ignoring server provided failover partner, we must pass in the original failover partner from the connection string.
// Otherwise the pool group's failover partner designation will be updated to point to the server provided value.
string actualFailoverPartner = LocalAppContextSwitches.IgnoreServerProvidedFailoverPartner ? failoverHost : ServerProvidedFailoverPartner;

PoolGroupProviderInfo.FailoverCheck(useFailoverHost, connectionOptions, actualFailoverPartner);
}
CurrentDataSource = (useFailoverHost ? failoverHost : primaryServerInfo.UserServerName);
}
Expand Down Expand Up @@ -2267,7 +2274,7 @@ internal void OnEnvChange(SqlEnvChange rec)
break;

case TdsEnums.ENV_LOGSHIPNODE:
_currentFailoverPartner = rec._newValue;
ServerProvidedFailoverPartner = rec._newValue;
break;

case TdsEnums.ENV_PROMOTETRANSACTION:
Expand Down
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